import os
import time
import fmt

fmt.printf('hello %v, nice: %v, %%, float: %v\n', 'world', 12, 3.1415, 233)

var s = fmt.sprintf('err msg=%v, count=%v', 'this is failed', 253)
println(s, 'len=', s.len)

string str =  time.now().datetime()
fmt.printf('err msg=%v, %v, count=%v\n', 'time in', str,253)

fmt.printf('%0d\n', -12)
fmt.printf('%0d\n', 12)

fmt.printf('|%5d|\n', -12)
fmt.printf('|%5d|\n', 12)

fmt.printf('|%010d|\n', -12)
fmt.printf('|%010d|\n', 12)